The present invention relates to equipment for producing cheese, such as mozzarella; and more particularly to equipment for cooling and salting newly formed blocks of cheese.
Mozzarella cheese is commonly produced in five to twenty pound blocks or cylinders which are molded at a typical temperature of 135 degrees Fahrenheit. At this temperature the cheese block is very soft and can be miss-shapened if not handled with care. Thus, before the cheese can be packaged, the blocks have to be cooled to approximately fifty degrees Fahrenheit. In addition, salt has to be added to the cheese if it was not already added prior to the molding step. The finished product has from one to two percent salt by weight.
There are two processes presently being employed to cool the cheese and add salt after molding. In the first method, cheese emerging from the molding equipment drops into a serpentine open channel, or flume, through which a brine flows. Cheese floats in a saturated brine, but sinks in fresh water. The brine flowing through the flume is cooled by refrigeration system to between 30 and 35 degrees Fahrenheit. The flume is sufficiently long so that cheese will be cooled to the desired temperature prior to packaging.
A drawback of the open flume system is that the cheese is not fully submerged and the upper surface, which is exposed to air, is not adequately cooled or salted. The exposed portion also dries out and becomes discolored if the block is not turned over periodically alone the flume. In addition hydraulic pressure tends to produce cupping of the top and bottom surfaces of the cheese blocks and bulging of the sides. Thus, workers must be positioned along the flume with tools to rotate the cheese blocks periodically to ensure uniform cooling and salting and to prevent deformation. This becomes very labor intensive.
A second cheese cooling system involves submerging the cheese in a large tank or pool of cooled brine. Typically the cheese blocks emerging from the molding machine are placed into baskets which are then mechanically lowered into the brine pool by an operator. This method ensures that all surfaces of the cheese are exposed to the brine and thus are cooled and salted uniformly. However, the submerging system still requires human operators to assist in filling and emptying the baskets of cheese and manual monitoring of the time that each basket has been in the brine to know when cooling is complete. In addition, the last cheese block to be placed into the basket usually is the first one taken out, thereby resulting is some blocks being in the brine longer than others, which produces blocks with different salt content and temperature.
Regardless of which conventional cooling method is used, a high level of manual labor and supervision is required. Therefore, it is desirable to provide a more automated and efficient process for uniformly cooling and salting cheese products.
The present invention is directed toward an apparatus to automatically ensure that freshly molded blocks of cheese are uniformly cooled and salted.
Such cheese cooling apparatus includes a tank having a cheese inlet and a cheese outlet. An inlet flume system is coupled to the cheese inlet and an outlet flume system is connected to the cheese outlet of the tank. A fluid circulation system produces a flow of liquid, such as water or brine, through the inlet flume, the tank and the outlet flume, whereby blocks of cheese are carried by that liquid flow.
The blocks of cheese are held in a carousel within the tank. That carousel includes a plurality of receptacles for the cheese blocks and a drive mechanism which moves each receptacle vertically through the tank to submerge the cheese. The drive mechanism sequentially aligns each receptacle with the cheese inlet to receive blocks of cheese from the inlet flume and selectively aligns each receptacle with the cheese outlet to enable cooled blocks of cheese to enter the outlet flume.
In the preferred embodiment of the cheese cooling apparatus, the tank is subdivided into a plurality of cooling cells that are fed with cheese blocks from a common inlet flume. A series of control gates, operated by an electronic controller, selectively direct cheese blocks from the inlet flume through the cheese inlet of a selected cooling cell. As the blocks of cheese enter the cooling cell, its carousel is indexed by the electronic controller so that the receptacles are filled with newly made cheese blocks. The fluid flow through the cooling cell also sequentially carries previously stored cheese blocks from the receptacles into the outlet flume and on to other processing equipment.
Another aspect of the present invention is a liquid circulation system that comprises flume and cooling circuits. The flume circuit produces a liquid flow that carries the blocks of cheese through the cooling apparatus. The cooling circuit has a liquid reservoir and a distribution conduit with a first pump and a heat exchanger connected in series between the liquid reservoir and the distribution conduit. A plurality of valves are operated by a controller to selectively apply liquid from the distribution conduit to a selected cooling cell. The cooling circuit also has a mechanism for transferring the liquid among the cooling cells in a daisy chain manner, whereby the chilled liquid preferably flows from the cell with the coldest cheese to the cell with the warmest cheese blocks. The liquid then flows from the cell with the warmest cheese back to the reservoir.